While I have my betta in a separate tank for fin rot, I noticed one of his decorations rusted inside the tank. I didn't even know it had metal wire in it! I took the decoration out and threw it away, but should I change out the water ASAP? I know the rust lets poison chemicals off into the water, but I don't know just how long the rust was there...

It was one of the "Zoo Med Betta plants". The kind that comes with a suction cup to attach to your wall. I warn you now, just don't buy them! I just learned the hard way!

I would take out decor and rinse it, do a good gravel vac (especially where it sat), and then a full water change. In fact, I would let the fresh water sit in it a day and do it again! I wouldn't do a full on scrubbing unless you have inverts. Also, keep an eye on your betta while he is in QT for signs of other problems. Otherwise, treat him as you normally would for his problem.Posted via Mobile Device

I would take out decor and rinse it, do a good gravel vac (especially where it sat), and then a full water change. In fact, I would let the fresh water sit in it a day and do it again!Posted via Mobile Device

I have sand that I just put into the tank the other day, sadly I think it's going to be harder to clean or would the sand be safe to leave in since I have no real way to effectively clean it?. I got lucky my boy wasn't in his tank when I noticed the rust! I'm already paranoid because of the Penn-Plax rust topic I saw on here the other day.

Ugh, this is just horrible when you can't even trust fish decorations in your tank! And I just got done redecorating it after a 100% water and substrate change too ): Now I'll probably have to do it again tomorrow. (It's almost midnight here, and I only noticed because I went to turn out the tank light and saw the brown rust stains)

Do you have a siphon? I have that kind of gravel vac and it works well with sand. You know? Big wide tube and small pipe that you have to suck on to get the waterflow going? And make sure to treat with a conditioner that helps with heavy metals like Prime.

You would be surprised how many decor items made for aquariums are in fact NOT aquarium safe! I always clean a new piece well and then soak it in a covered bucket for a week. I then inspect it with a fine tooth comb and test the water chem before I add it to my tank. It has really cut down on decor related issues. Also, the magnet test is GREAT for finding hidden metal as long as you use a strong one.Posted via Mobile Device

Do you have a siphon? I have that kind of gravel vac and it works well with sand. You know? Big wide tube and small pipe that you have to suck on to get the waterflow going? And make sure to treat with a conditioner that helps with heavy metals like Prime.Posted via Mobile Device

I have yet to find a siphon for 3-gallon tanks and under, and I have been looking and even tried to make my own, but to no avail ): So therefore all of my substrate is hand-washed and I get what waste I see with a turkey baster. The sand's only been in the tank for about 3 days though, so yeah. Where it rusted also never really touched the sand, just the water which I will be changing. I have API tap conditioner, is that a good conditioner for the heavy metal problem?

You would be surprised how many decor items made for aquariums are in fact NOT aquarium safe! I always clean a new piece well and then soak it in a covered bucket for a week. I then inspect it with a fine tooth comb and test the water chem before I add it to my tank. It has really cut down on decor related issues.Posted via Mobile Device

And I actually go through and check everything I buy now! The plant I had actually was in that tank for a few months before this happened, and now I can't even trust my old decorations. *mind you, I only have 5 but still* Luckily my other boy doesn't have this issue to be dealt with yet since his tank goes undecorated for cleaning purposes (his tank is too small for a filter, but I do plan to upgrade that on the 30th) but it still is a huge concern.